Tuning Thermo-Mechanical Properties of Shape Memory Polymer Foams for Biomedical Applications

Amorphous, thermoset low-density shape memory polymer (SMP) foams have been studied for their use in biomedical applications, specifically as embolic agents. These SMP systems were fine-tuned over the years to tailor their thermo-mechanical response and actuation profiles to better suit a clinical application. Characterization studies conducted by Singhal et al. (2013) and Hasan et al. (2014) demonstrated adaptable thermal and actuation profiles as well as material hydrophobicity by modifying the chemical constituents that make the polymer network. A new study shows that the SMP properties can be further tailored by adjusting the stoichiometric quantities of a chemical blowing agent used during the foam fabrication process. This research evaluates changes to the chemical structure, glass transition temperature, and mechanical properties of the resulting SMP foams as a direct result of varying the blowing agent content. Additionally, actuation profiles and shape memory behavior of these new systems are explored in this work. Modifying quantities of the chemical blowing agent during the foam blowing process serves as an additional tool for fabricating polymeric materials with desirable and adjustable properties.